// 模拟ios原生0.5像素边框
// $c 边框颜色
@mixin line-top($c: $border){
  content: " ";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 1px;
  z-index: 1;
  border-top: 1px solid $c;
  transform-origin: 0 0;
  transform: scaleY(0.5);
}

@mixin line-bottom($c: $border){
  content: " ";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  z-index: 1;
  border-bottom: 1px solid $c;
  transform-origin: 0 100%;
  transform: scaleY(0.5);
}

@mixin line-left($c: $border){
  content: " ";
  position: absolute;
  left: 0;
  top: 0;
  z-index: 1;
  width: 1px;
  height: 100%;
  border-left: 1px solid $c;
  transform-origin: 0 0;
  transform: scaleX(0.5);
}

@mixin line-right($c: $border){
  content: " ";
  position: absolute;
  right: 0;
  top: 0;
  z-index: 1;
  width: 1px;
  height: 100%;
  border-right: 1px solid $c;
  transform-origin: 100% 0;
  transform: scaleX(0.5);
}